Exploring the route choice of slime mold in a ballistic logic gate maze in different conditions

Abstract

This study investigates the factors affecting the smart behavior of slime mold, a single-celled simple organism, in a ballistic logic gate maze. The slime mold can choose between the two output sites marked by food and act as a decision-making logic gate that can be applied in biological computing and other logic-requiring operations. The molds were hypothesized to have direction-determining abilities, which allowed them to choose a straight path starting from a dead-end and grow without turning until another dead-end was reached. Experiments as primary research are conducted for six groups of slime mold, varying in food type on the output site, and the stress level of the mold is determined by the fed/unfed status. Incorporating evidence from time-stamped photographs recorded over a 20-hour period, our analysis shows a strong correlation between the speeds of growing/food covering and the slime mold’s stress level. We concluded that the unfed slime mold grows slower on agar gel but covers the food faster and thus has a greater overall speed in completing the logic gate. The speed of covering the food is the fastest on oats, followed by yogurt, and is the slowest on apple slices. The results of the success rate regarding the straight-through growing behaviour of the slime mold are lower than expected. While accessing limited sample size during the experiment, this study questions the reliability of the slime mold direction pattern and recommends further research and confirmations on the issue.